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A B
Figs. 20.5A to C: Congenital nasal pyriform
aperture stenosis (CNPAS).(A)Medialbowing
and overgrowth of medial nasal process of
themaxilla(arrow),narrowingofanteriorpyriform
apertureofless11mm(arrows).(B)Triangularshapedhardpalate.(C)Bonyridgeintheundersurface of hard palate (arrow) and “box”-
C
shapedanterioraperture(box).
265Chapter 20 Pediatric Sinonasal Disorders: Imaging
Nasal Cavity Anomalies
Congenital nasal pyriform aperture stenosis:
■ Congenital nasal pyriform aperture stenosis (CNPAS) is a congenital
anomaly characterized by narrowing of the anterior bony nasal passage,
most often bilateral.
■ Pathogenesis: It results from the deciency of primary palate derived
from midline mesodermal tissue, with dysplasia/overgrowth of nasal
processes of maxilla.
■ Clinical features:
• Presents in newborns or infants in rst few months of life.
• Constitutes one-fth to one-third of cases of congenital airway
obstruction.
• Presents with respiratory distress, which may be triggered after
respiratory infection. Cyanosis may be present.
• It is dicult to pass nasogastric tube in these neonates.
• Imaging—best modality is multidetector computed tomography
(MDCT) mainly axial and coronal planes (Figs. 20.5A to C).
Imaging ndings include:
▶ Medial deviation of anterior maxillae with inward bowing of the
maxillary spines.
▶ ickening of nasal processes.
2
Section 5 Congenital/Pediatric Diseases266
▶ For narrowing of the PA, less than 11 mm in term infant is
considered diagnostic.
▶ No standard measurements exist for the normal PA; few studies
quote PA width 13.4–15.6 mm as normal and PA area of 0.7–
1.1 cm2 as normal. In CNPAS, the PA width is reduced to 4.8–
7.0 mm and PA area is reduced to 0.2–0.4 cm2.
▶ Abnormal maxillary dentition: Solitary median maxillary central
incisor syndrome (SMMCI) is seen in 75% of cases.
▶ Triangle-shaped palate seen as a bony ridge along the oral
surface of hard palate on coronal images.
▶ Posterior choanae are normal.
▶ e anterior aperture is “box”-shaped as opposed to normal
triangular shape.
▶ Associated with holoprosencephaly, hypopituitarism, absent
olfactory bulbs [brain MRI/cranial ultrasonography (USG)
recommended routinely].
■ Management:
• It generally has a good prognosis, as the nasal cavity grows eventually
and obstruction is relieved.
• Severe cases having persistent respiratory diculty and poor weight
gain may require surgical reconstruction with stent placement, sub labial
resection of the anteromedial maxilla, or reconstruction of the anterior
nasal passage.
Choanal Atresia
3
■ Choanal atresia is the most common nasal congenital anomaly.
■ It is more often unilateral then bilateral.
■ Choanal openings refer to a pair of posterior apertures of the nasal cavity
that open into the nasopharynx.
■ Terminology:
• Atresia: Complete obstruction of the posterior choanal openings.
• Stenosis: Narrowing of the posterior choanal opening/nasal passage.
ere are three types:
1. Bony (85–90%): is is the most common variant.
2. Membranous (10–15%).
3. Mixed/osseomembranous is a combined type of abnormality.
Pathogenesis:
■ Failure of perforation of embryonic oronasal membrane at 7th week.
■ Retinoic acid receptor developmental error also implicated.
Associated syndromes: CHARGE syndrome (most important), Apert
syndrome, Crouzon syndrome, and DiGeorge syndrome.
Clinical features:
■ Bilateral: Neonate/infant with respiratory distress, aggravated by feeding,
failure to pass nasogastric tube beyond 3–4 cm, usually associated with
syndromes.
A B
Figs. 20.6A and B: Unilateral bony choanal atresia. (A)Computedtomography(CT)axial
imageshowingmedial bowing of posterior lateral nasal walls(arrow),thickvomer (arrowhead), nasal cavity lled with uid (asterisk). (B) CoronalCT shows bony plate occluding the
posteriorchoana(arrow).
■ Unilateral: Child/young adult with chronic purulent unilateral rhinorrhea with mild respiratory diculty, usually isolated anomaly.
Imaging modality:
■ Best modality is thin section MDCT interpreted in axial and sagittal
planes with 3D reconstruction for surgical planning.
■ CT should be performed after suctioning and after instillation of nasal
decongestants.
Imaging ndings (Figs. 20.6A and B):
■ Medial bowing of the posterior lateral nasal walls (posterior maxilla).
■ ickening of vomer—may fuse with maxilla.
■ Bony type—bony plate occludes the choana.
■ Membranous type—soft tissue membrane (which may be thin and strand
like or thick and plug like) occludes the choana.
■ Nasal cavity may be lled with soft tissue/uid/inferior turbinates.
■ Size criteria: ickening of vomer more than 2.4 mm; narrowing of
choanae less than 3.4 mm.
Management:
■ In a newborn with bilateral atresia there is a need to establish immediate
oral airway.
■ In choanal stenosis, conservative management can be done, allowing
natural growth of nasal cavity.
■ For unilateral obstruction, denitive treatment delayed up to 6–9 years
(midface develops).
■ For bilateral obstruction, surgical management is necessary. Common
surgeries performed include:
• Endoscopic perforation of thin membranes
267Chapter 20 Pediatric Sinonasal Disorders: Imaging
Section 5 Congenital/Pediatric Diseases268
A
C
Figs. 20.7A to D: Nasolacrimal duct (NLD) stenosis.(A)Rightmedialcanthusisswollen
secondarytodacryocystitis(arrow).(BandC)Coronalobliqueimagesshowmildnarrowing
oftheproximalrightNLDcomparedtoleftside(arrows).(D)Sagittalobliqueimageshowing
thenarrowedNLDwithsecretions(arrow).
B
D
• Transpalatal resection of vomer with choanal reconstruction
• Stent placement.
Nasolacrimal Apparatus Anomalies
■ ese include NLD stenosis, congenital dacryocystocele, and dacryocystitis.
Embryology: e valve of Hasner, located at the opening of the NLD within
the nasal cavity, is imperforate in up to 70% of newborns resulting in NLD
obstruction. Spontaneous opening of an imperforate valve of Hasner usually
occurs within 6–12 months.
Nasolacrimal duct stenosis:
■ It results from partial persistence of the Hasner membrane.
■ Imaging—may be normal or show accumulation of secretions within an
enlarged nasolacrimal duct proximal to stenosis (Figs. 20.7A to D).
■ Treatment: Duct massage followed by duct probing or ductal intubation
is done (depending on the response); 90% resolve within a year.
Congenital dacryocystocele:
■ Synonym: Nasolacrimal duct mucoceles.
■ ese result due to obstruction of both the proximal and distal ends of
the nasolacrimal duct.
Fig. 20.8: Infected bilateral dacryocystoceles. Coronal contrast-enhanced computed tomo-
graphy(CECT)imageshowsbilateralcysticdilatationofthenasolacrimalducts(NLDs)with
peripheralenhancementsuggestiveofsecondaryinfection(arrows).
■ Pathogenesis:
• Distal block occurs due to an imperforate Hasner membrane.
• Proximal block occurs due to nasolacrimal sac distension or an
anatomic variation compresses proximal valve.
■ Clinical features:
• Patient presents with epiphora or cellulitis (preseptal).
• Proximal lesion is seen as small, tense, and bluish medial canthus
mass at birth or shortly after birth.
• Distal lesion is seen as submucosal nasal cavity mass at inferior
meatus, may even cause respiratory distress, if bilateral.
• It is more frequent in females (female > male = 3:1).
■ Complications: Nasal obstruction, infection (dacryocystitis), and rupture.
Imaging ndings include (Fig. 20.8):
Computed tomography/MRI—both CT and MRI can be used, multiplanar
reconstruction is important:
■ Nasolacrimal duct dilatation.
■ Well-dened, thin-walled mass with uid attenuation/signal intensity
involving the medial canthus or nasal cavity.
■ Contiguity of the mass with the enlarged NLD can be demonstrated.
■ Superior displacement of the inferior turbinate.
■ Contralateral shift of the nasal septum.
■ Postcontrast slight enhancement of the cyst wall (unless dacryocystitis
when thick enhancement can be seen).
Treatment:
■ Dacryocystoceles require prompt treatment due to a tendency to become
infected and cause subsequent permanent damage to nasolacrimal system.
269Chapter 20 Pediatric Sinonasal Disorders: Imaging
Section 5 Congenital/Pediatric Diseases270
Table 20.3: Dierence between congenital dacryocystocele
and dermoid/epidermoid.
Congenital dacryocystocele Dermoid/epidermoid
Location Medial canthus Lateralcanthus(morecommon)
Fat density Absent Present in 50%
Rim enhancement Usually absent Thin rim enhancement common
Calcication Absent May be seen
ContiguitywithNLD Present Absent
(NLD:Nasolacrimalduct).
A B
Figs. 20.9A and B:(A)Dacryocystoceleversus(B)dermoid.
■ Graded treatment is done: Manual pressure, probing—irrigation—
endoscopic resection—marsupialization in severe cases, depending on
the response.
■ Dacryocystoceles closely resemble medial canthus dermoids, dierentiating points are highlighted in Table 20.3 and corresponding Figures
20.9A and B.
INFECTIVE OR INFLAMMATORY PEDIATRIC SINONASAL DISORDERS
Rhinosinusitis
Role of imaging in acute sinusitis is limited to evaluation of suspected complications. Amongst complications, orbital complications such as cellulitis and
subperiosteal abscess are more frequent in children.
Acute Sinusitis
■ It is dicult to dierentiate viral rhinosinusitis versus bacterial sinusitis
on radiology.
■ Imaging may show only opacication of sinuses. Although air-uid levels
are more commonly seen in acute sinusitis (Fig. 20.10A).
A B
Figs. 20.10A and B:(A)Acuteonchronicsinusitis 11years/female.Airuid levelsseenin
bilateralmaxillary sinuses. Mucoperiostealthickening (arrow) alsonoted in both maxillary
sinuses.(B) Intrasinus synechiae. Chronic sinusitiscanleadtoformationof bands of scar
tissue(arrows)stretchingbetweenlateralandmedialsurfacesofmaxillarysinuses.
■ Uncomplicated acute sinusitis is a clinical diagnosis (no imaging is
required).
Complications of acute sinusitis:
1. Subperiosteal abscess:
• Most common intraorbital complication in children.
• If suspecting sinusitis complications, a CECT scan should be
performed.
• Orbital complications are frequently from ethmoid sinusitis.
2. Osteomyelitis and Pott’s puy tumor:
• To nd subtle osteomyelitis, pay attention to the bone adjacent to
the area of most prominent soft tissue swelling.
• MRI can show early phase of osteomyelitis as bone edema and
enhancement.
3. Intracranial abscess
4. Intrasinus synechiae (Fig. 20.10B)
5. Subdural empyema
6. Cavernous sinus thrombosis: Cranial nerve palsy in the setting
of orbital or sinus infection should raise the suspicion of this
complication.
7. Pyomyositis
8. Infectious optic neuritis.
Chronic Sinusitis
■ Pediatric chronic sinusitis may be associated with certain predisposing
factors, which include:
• Recurrent upper respiratory tract infection (URI)
• Mucociliary deciency, cystic brosis (CF) (seen in nearly 100% of
children with CF)
271Chapter 20 Pediatric Sinonasal Disorders: Imaging
Section 5 Congenital/Pediatric Diseases272
• Allergy
• Gastroesophageal reux disease
• Chronic systemic disorders, such as vasculitis and immunodeciency.
TUMORS AND TUMOR-LIKE CONDITIONS
Tumors and tumor-like conditions encountered in neonates, infants, and
older children according to the age of occurrence are enlisted in Table 20.2.
e spectrum of tumors occurring in pediatric age group resemble those in
adults and several individual entities, such as rhabdomyosarcoma, Juvenile
nasopharyngeal angiobroma, and lymphoma have been covered elsewhere
in the book (see Chapters 12 and 14). Also see illustrative cases at the end of
this chapter.
Some of the tumors and tumor-like conditions seen in pediatric age are
discussed below.
Infantile Frontonasal Capillary Hemangioma4
■ Hemangioma is the most common benign tumor in an infant.
■ ese show a proliferative growth phase (during the 1st year) and an
involutional phase (after the 1st year). However, some of them may not
involute (noninvoluting hemangioma).
■ Clinical dierential diagnosis is nasal glioma, as both might present with
a bluish or reddish mass.
■ Association: PHACE syndrome refers to—posterior fossa brain
malformations, hemangioma, arterial anomalies, coarctation of the
aorta, cardiac defects, and eye abnormalities.
■ Ultrasonography—soft tissue mass with intense vascularity showing
arterial ow channels representing feeding vessels.
■ Computed tomography—intensely enhancing mass in subcutaneous
plane in frontonasal region, nasal ala, nasolabial region, or anywhere
within the nasal cavity. CT important to rule out bony involvement/bony
origin, which is seen in intraosseous cavernous hemangiomas (Figs.
20.11A and B).
■ e MRI shows a lobular mass, on T1WI mass is mildly hyperintense
and is hyperintense on T2WI with hypointense internal ow voids.
■ On contrast-enhanced magnetic resonance imaging (CEMRI), the mass
show intense postcontrast enhancement. In the involuting stage, heterogeneous enhancement is noted.
Teratoma
■ Teratomas are tumors containing elements from the three embryonic
layers (ectoderm, mesoderm, and endoderm).
■ ese are frequently benign, though malignant forms may also occur.
■ ese may occur in the sinuses, within the nasal cavity or nasopharynx.
■ Teratomas represent spontaneous and autonomous new growth of tissue
foreign to a region.
A B
Figs. 20.11A and B: (A) Capillary hemangioma in a 3 years/female. Contrast-enhanced
computed tomography (CECT) shows lobular, intensely enhancing mass in skin and
subcutaneoustissueanteriortonasalboneonleftside.(B)Nasal“bone”hemangiomaina
4years/female. CECT images showing anavidlyenhancingsofttissuedensitylesion with
bonedensitywithinitgiving“sunburstappearance”arisingfromrightnasalbone.
■ Clinically sessile or pedunculated masses, which may protrude through
the mouth, are seen.
■ Anencephaly, hemicrania, and palatal ssures may be associated.
■ Can be detected in utero and are associated with polyhydramnios.
■ Imaging ndings include soft tissue mass with presence of calcication,
fat, tooth, and may show cystic areas within. Majority of them do not
show intracranial extension.
■ Treatment is complete excision.
Hamartoma
■ Hamartomas are rare lesions involving the abnormal growth of any of the
three germinal layers, which are normally indigenous to a region.
■ Location: Oral cavity, nasal cavity, tongue, nasopharynx, Eustachian
tube, hypopharynx, or larynx.
■ In nasal cavity, sites reported—septum, ethmoid, vestibule, and maxillary
sinuses.
■ In head and neck region, these are mostly composed of vascular tissue.
■ Imaging ndings are nonspecic. CT shows a well-marginated and
homogenous soft tissue mass. It may or may not show enhancement and
do not show calcication.
■ ese tumors have limited growth potential and surgical resection is the
treatment of choice.
Lipoblastoma
■ Rare benign and circumscribed mesenchymal tumors of embryonal fat.
■ e CT and MRI—entire fat-containing tumor, cannot be distinguished
from lipoma on imaging.
273Chapter 20 Pediatric Sinonasal Disorders: Imaging
Section 5 Congenital/Pediatric Diseases274
Sinonasal Nerve Sheath Tumors
5
■ ese are uncommon lesions, which represent less than 4% of head and
neck nerve sheath tumors (schwannomas).
■ Aected age group varies from childhood to elderly (0–78 years with no
sex or racial predilection).
■ Symptoms are nonspecic, such as nasal obstruction, epistaxis, and
anosmia.
■ e CT shows an expansile and mildly enhancing mass with no bone
remodeling may be appreciated.
■ e MR imaging shows an intermediate T1 and variable T2 signal
intensity (Figs. 20.12A to D).
■ Sometimes intracranial extension through cribriform plate may be seen.
■ Histopathology remains gold standard for diagnosis.
A
C
Figs. 20.12A to D:Nasalbenignnervesheathtumor.(AandB)AxialandcoronalT2-weighted
images show intermediate hyperintense mass in the nasal cavity with intracranial and
extraduralextension. (C)T1coronalimageshows hypointense signal. (D)T1postcontrast
showshomogenousenhancement.
B
D
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